Walmart offers the Disney Cars Soft Potty and Step Stool (pictured) for $13.42. (Amazon offers it for the same price for Prime members.) Opt for Site-to-Store pickup to avoid the $4.97 shipping charge. That's $10 off and the lowest total price we could find. Features include a built-in deflector and polyurethane foam padding.

Also available is the Disney Fairies Soft Potty and Step Stool for $17.92. Opt for Site-to-Store pickup to dodge the $4.97 shipping charge. That's $5 off and the lowest total price we could find. It has the same features as above.